Soot blower



E. HAHN sooT BLOWER June 20, 1939.

Filed Dec. 8, 1935 mj L? x i y 5 m,

Patented June 20, 1939 GFFl-QE 3 Claims.

This invention relates to improvements in apparatus for removing soot and iiy-ash from the tubes of nre-tube boilers, economizers and the like, and a principal object of the invention is to provide a device of this class that shall be functionally precise and highly efficient in operation.

Another object of the invention is to provide a soot-blower of the stated type having novel and improved adjustment means for properly positioning and aligning the apparatus with the tubes.

Still another object of the invention is to provide a soot-blower of novel construction adapted for efficient cleaning both of the direct and return tubes of boilers of the so-called locomotive and nre-box types.

The aforesaid principal objects as well as others hereinafter set forth are attained by the novel construction and arrangements illustrated in the attached drawing, in which:

Figure l is a front elevational view of a boiler of the locomotive type with the front smoke-box door removed;

Fig. 2 is a longitudinal vertical sectional view of the boiler;

Fig. 3 is a fragmentary rear elevational view with the rear smoke-box door removed;

Fig. 4 is a diagrammatic view showing one each of the direct and return tubes of the boiler, and illustrating a functional feature of the invention;

Figs. 5 and 6 are respectively, top plan and side views of one of the clamps constituting an element of my apparatus, and

Figs. 7 and 8 are, respectively, top plan and side elevational views or one of the aligning elements also constituting a novel feature of the apparatus.

With reference to Figs. 1, 2 and 3 of the drawing, the boiler furnace therein illustrated, of well known type, comprises the usual combustion chamber l and grate 2. From the rire-box l the heated gases pass rearwardly through the direct tubes 3 of the boiler, as indicated by the arrows, to the rear smoke-box 4, and from the rear smoke-box the gases then move forwardly through the return tubes 5 to the front smokebox 6, from whence they pass to the stack l. The tubes 3 and 5 extend through the usual boiler shells il and 9 which contain the water to be converted into steam, and the steam collected in the upper portions of the shells B and 9 is withdrawn in the usual manner for the required purpose. is provided with a removable door I l and a similar removable door l2 is provided at the front of the shell 9 and fire-box 6.

It will be noted that the rear smoke-box 4' ln accordance with my invention, I provide a pair of pipey frames l which are mounted, as shown, in the front smoke-box 6, and each of which comprises a header i3 and a series ofy depending tubes le. The headers I3 are in the present instance mounted in alignment with the upper horizontal row of return tubes 5, and each of the depending tubes lll is in alignment with one of the vertical rows or the said tubes so that all of said tubes are embraced by the pipe frame. As shown in Fig. 2, the headers i3 and tubes lli are supported, by means hereinafter described, in ad Vance of the forward ends of the tubes 5, and both the headers and the tubes i4 are provided with a series of nozzles l5, each of which nozzles is aligned with one of the tubes 5. From each of the headers I3, a pipe l extends to a valve il, and through this valve is connected with a supply line I3 extending to a source of compressed air or steam supply, as the case may be.

Mounted in the rear smoke-box by means hereinafter described is a corresponding set of pipe frames 2a comprising headers 2 l, 2i, aligned with one of the horizontal rows of the direct liretubes 3, and tubes 22 which in turn are aligned with the respective vertical rows of the tubes 3. Each of the headers 2l and the tubes 22 is provided with a series of nozzles 23 which are accurately aligned with the rear ends of the lire-tubes 3 in a manner corresponding to the alignment'of the nozzles l previously described with the return tubes 5'. From each of the headers 2| a pipe 2d extends upwardly to the top ofthe shell 8, and forwardly to the front of the boiler where they connect with the valve Il as shown. It is apparent that with this arrangement and controlled by the valve Il at the front of the boiler, jets of steam or compressed air may be directed through the nozzles l5 into the front ends of and rearwardly through the return tubes 5; and through the nozzles 23 into the rear ends of and forwardly through the direct tubes 3.

The eiective removal of soot or fly-ash from fire-tube boilers by blower apparatus of the genn eral character described above requires that the nozzles through which the steam and air is injected into the tubes be located exactly in the center of or in axial alignment with each tube so that the expanding force or blast of the injected uid will carryA through the full length oi the tube without losing force by impinging on the tube Walls. Unless this true alignment i's obtained and maintained, it is practically impossible to effectively free the tubes of the accumulated soot or fly-ash, since if the force of the blast-is spent due to misalignment of the nozzles with the tubes, the soot and fly-ash at the ends of the tubes remote to the nozzles is not effectively removed. It is necessary also for maximum effectiveness that the expanding force of the steam or compressed air injected into the tubes shall be directed against the formation of the successive layers of soot or fly-ash within the tubes, i. e., counter to the normal flow of the combustion gases through the tubes so that these layers which are deposited in shingled formation may be adequately broken away from and scoured from the sides of the tubes. This characteristic formation of soot and ash within boiler fire-tubes is illustrated roughly in Fig. 4, wherein it will be noted that the formation within the direct tubes 3 in which the gases flow from front to rear is the exact reverse of that within the return tubes 5, wherein the flow of the combustion gases is from the rear of the furnace toward the front. The slight irregularity or lapped formation of the deposit forms a benecial, even though slight, resistance to the expanding force or blast of the injected fluid when the latter is directed in the counter-draft direction, and thereby materally increases the effectiveness of the blast to free the deposits from the walls.

The first of these requirements is fully met in my apparatus by the use of relatively fixed nozzles, that is, nozzles which are permanently iixed in the properly aligned positions with respect to the tubes. The original installation of the blower apparatus in this properly aligned position is accomplished in accordance with my invention by means of the devices illustrated in Figs. 5 to 8, inclusive. The header and tube assemblies i3 it and Zi--Q are supported in spaced relation to the front and rear tube sheets respectively by means of the brackets illustrated in Figs. 5 and 6. Each of these brackets comprises a main bracket arm 25 which carries at its outer end a clamp 26 by means of which the arm may be rigidly secured to one of the tubes lli or 22. The inner end of the arm 25 is offset as indicated at El and is adapted to occupy a position in the interior of one of the fire-tubes. A clamping bar 28 inserted in an adjoining vertically aligned nre-tube is secured to the arm E5 by means of a bolt 29, and at the outer end of the bar 2S and spaced from the bolt 29 is a set screw 3i which is adapted to bear against the outer end portion of the arm 25 as illustrated. By means of the adjustable clamp 25 which secures the arm 25 to the tubes lLi, the header and tube assemblies may be very accurately adjusted with respect to the nre-tubes to obtain the required correct axially aligned relation between the nozzles l5 and the tubes 5. At the same time, the bolt 29 and set screw 3l insure a rigid and parrnanently secure connection between the boiler and the bracket arm 25. In order to insure the required accurate parallel relation between the tubes I4 of the blower assemblies and the tube-sheet of the boiler, I provide the adjustable spacer elements illustrated in Figs. 7 and 8. These elements comprise a clamp Si adapted to be rigidly secured to one or more of the tubes ifi of the blower assemblies and to project inwardly toward the tube-sheet 32 of the boiler. The inner end of the clamp 3l is provided in the present instance with a socket for reception of a pin 33, and this pin is secured in the socket for adjustment by a set screw Bil. The pin 33 as illustrated is adapted to bear against the tubesheet 32 between the adjoining tubes 5. These rspacer elements are adjusted in the original installation to afford the proper parallel relation between the tubes i4 and the sheet 32, and they provide for subsequent adjustment to maintain this true parallel relation in the event of any distortion occurring in the blower pipe frame arising from the effects of the heat within the smoke-box to which the said pipe frame is subjected.

The means for mounting and adjusting that portion of the blower apparatus which occupies the rear smoke-box 4 and which is adapted to clear the direct lire-tubes 3 of the soot and ash deposit is substantially identical with that described above. In this case, however, two of the support brackets i5 are employed for each of the pipe frames, It will be noted that the valve ll located at the front of the boiler provides for operation of both portions of the blower apparatus from a convenient centralized point, and this valve preferably is of a character permitting the operator to direct the steam or compressed air to each of the pipe frames individually.

By providing the two sets of nozzle structures, one at the front of the boiler in operative relation with the return tubes and the other at the rear o1" the boiler in operative relation with the direct tubes, my device not only makes possible the cleaning of both the direct and return tubes but also provides for the cleaning of these tubes in the most eilicient and eiective manner by directing the steam or compressed air through the tubes in the counter-draft direction, which as described above takes advantage of the normally irregular soot formation, Furthermore, the arrangement provides through the common control valve il for actuation of the entire device from a single readily available operating station preferably at the front of the boiler and with a mini-- mum interruption and disturbance of boiler operation.

I claim:

l.. In a soot-blower for fire-tube boilers, the combination with a nozzle structure of means for mounting said structure on the tube sheet of said boiler in operative relation to said tubes7 said means comprising a bracket arm adapted to enter one of said tubes and means for rigidly clamping arm to the nozzle structure, a clamping bar adapted to enter an adjacent tube and to project from said tube toward the nozzle structure, a bolt for drawing said bar toward the arm, and a set 'crow threaded into the projecting end of said bar and arranged to bear against the arm, said bolt being positioned intermediate the said set screw and said tube sheet.

2. In a soot-blower or iire-tube boilers, the combination with a nozzle structure, of means for mounting said structure in proximity to the tube sheet of said boiler in operative relation to said tubes, said means comprising a bracket arm extending into one of said tubes and means for rigidly clamping said arm to the nozzle structure, a clamping bar extending into an adjoining tube and projecting from the tube toward said nozzle structure, a bolt for drawing said bar toward the arm and positioned relatively close to the tube sheet, and a set screw threaded into the projecting end of said bar in position relatively remote to the tube sheet and arranged to bear against the arm, said bolt and set screw constituting a joint means for securely clamping said bar and arm together upon said tubes.

3. In a soot-blower for iire-tube boilers, the combination with a nozzle structure adapted for mounting at an end of the boiler tube assembly and comprising a plurality of relatively spaced nozzle elements arranged in said structure for alignment respectively with the individual tubes of said assembly, and means for mounting said structure in the operative position, said means comprising a bracket, means for rigidly and adjustably clamping said bracket to one end of said structure, means for rigidly clamping said bracket to the said tubes, and means for adjustably locating the other end of said structure with respect to the tube ends, said clamping and locating means providing for adjustments of said structure to accurately center and align the nozzle elements with respect to the individual tubes.

EUGENE HAHN. 

